No HDMI output but the board is turned on

[mahmood]

[adexmont]

Hi,
hope my procedure may help you solving the booting problem :
1) Parallella board have 2 green leds + network port leds (4 led 3 green 1 orange) = if the 2 green leds on the board are not on, but only one , should mean that the boot process is not going well (maybe some mistake in bit.bin file)
2)when you dump the .img file on the sd card the "bs:4M" option looks like a must for me (without it the sd wasn't printed correctly.
3) i dumped first the headless version then overwrite the hdmi version without formatting (that may be useless because dd should overwrite the data but i'm not sure)
4) I dig in the github to retrieve the "correct" (not sure it is correct) .bit.bin file and overwrite / rename on the fat BOOT partition. (https://github.com/parallella/parallella-fpga)
5) i did overwrite the .dtb file from the hdmi version (should be the same but you can check with md5sum)
6) you can test if the board is working by checking the network device list of your router and by checking the ethernet port on parallella board if only the green let is blinking you r not online, if the orange is blinking you should be able to ssh the board. (headless image should run on hdmi version allowing you to access via ssh and (still headless) may work better than hdmi version)

I'm on a 7020 hdmi so the result may not be the same

hope to pointed you in a direction to solve your problem.

Cheers

A

[mahmood]

[adexmont]

dd bs=4M if=pubuntu.img of=/dev/sd* is done (in my case) via an usb adapter tht allow you to use the sd card as a usb pendrive, so without the needs of parallella board.
After that you insert the sd on parallella and boot up.

cheers


A

[mahmood]

Up to now, I think the problem is with powering up the board and not the sd card. I have provided to videos and appreciate if you check them and give me a feedback. I have attached a fan to the board according to the guides.

http://www.mediafire.com/file/rgv1g9chcpmhv6c/vid1.mp4
In vid1, before plugging the power cord to the board, the voltage is about 6V. As I plug the power, the voltage drops to about 2.5V the board LED is off but the fan spins at very low speed. If you see the video, when I unplug the power cable, the fan stops.

http://www.mediafire.com/file/8j645bqvv3nc3o9/vid2.mp4
In vid2, before pluggin the power cable, the voltage is about 11.5V. As I plug it, the voltage drops to about 3.5V. The green LED is on but there is no screen. Again, the fan spins and when I unplug the power, it stops.

BTW, I only see one green LED on the board. Why did you say there are two green LEDs?

What is wrong here?

[adexmont]

Why trying to give 12 V on a device that should work with a low tolerance 5 V ? (6 may be too much anyway, asking for tech confirmation) .

I think you fried the board but can't say exactly what component and how to repair.

Try to ask for repair @ adapteva or just buy another one.

I'm sorry for your board

A

[mahmood]

!!!!

Couple of things... Isn't there any voltage regulator on the board?! We usually put a simple ans small voltage regulator on a bread board with few things. Why there isn't such thing on a 100$ board?!
Also, why an 6V input power drops to about 2~3V after plugging the cable?

What is the procedure for board raepair?